Synanceia verrucosa is a fish species known as the reef stonefish or simply stonefish. It is a carnivorous ray-finned fish with venomous spines. It lives on reef bottoms camouflaged as a rock. It is the most venomous known fish in the world. It can be lethal to humans.[1][2]

The reef stonefish is the most venomous fish in the world.[4] Its dorsal area is lined with 13 spines, each of which has two venom sacs.[4] The spines are sharp and stiff and have been known to pierce boot soles.[5]

Effects of the venom include severe pain, shock, paralysis, and tissue death.[5] A large dose can be fatal to humans, generally young children, the elderly, and those with weakened immune systems. Medical treatment includes the antivenom. A local anesthetic can reduce the pain. First aid includes immersion of the affected limb in hot water; this is thought to help denature the proteins in the venom. The immobilization of venom at penetration site using a tourniquet or firm constrictive bandaging is no longer recommended.[6] Surviving victims may have nerve damage, which can lead to local muscle atrophy.